Sailing vessels



H- M. BARKLA SAILING VESSBLS Aug. 27, -1 957 4 Sheets-Sheet 1 Filed Jan. 19, 1954 flak /y 514 641 ,9

H. M. BARKLA SAILING VESSELS Aug. 27, 1957 4 Sheets-Sheet 2 Filed Jan. 19, 1954 27, 1 H. M. BARKLA 2,804,038

\ SAILING VESSELS Filed Jan. 19, 1954 4 Sheets-Sheet a v r We H. M. BARKLA SAILING VESSELS Aug. 27, 1957 4 Sheets-Sheet 4 Filed Jan. 19, 1954 AT TORNEYS United States Patent 2,804,038 SAILING VESSELS Hugh M. Barkla, St. Andrews, Fife, Scotland, assignor to The National Research Development Corporation, London, England, a corporate body of Great Britain and Northern Ireland Application January 19, 1954, Serial No. 404,845

16 Claims. (Cl. 114-66.5)

This invention relates to sailing vessels and has for an object the provision of sailing vessels which are capable of speeds considerably in excess of the speeds attainable by sailing vessels of orthodox design.

For sailing vessels to achieve speeds of the order of 30 to 40 knots in winds of a speed not exceeding the speed of the vessel, it is necessary that the sail area per ton should be of the order of 400 square feet for smaller craft and 150-200 square feet for larger craft, and also that the stability be adequate to permit generation of aerodynamic forces which are more or less equal to the unsubmerged weight of the vessel in large craft.

A sailing vessel according to the present invention comprises a plurality of spaced interconnected submerged hulls and at least one aerofoil system incorporating at least one rigid aerofoil supported by the hulls, the hulls and the aerofoil system being relatively movable about vertical axes.

The aerofoil system may incorporate two aerofoils which may taper and converge towards their tops where they may be linked by a horizontal spar. They may be joined near their lower extremities by the base member. A hull may be located at each of the four corners presented at the bottom of the said aerofoil system. Each hull may be independently rotatable about a vertical axis relatively to the aerofoil system. Each hull may carry a rudder.

In an alternative system there may be provided one aerofoil, or a plurality of aerofoils of symmetrical section rigidly interconnected and presenting the same angle of incidence to the wind, a wind vane operatively connected to the rudders being mounted on a movable boom extending aft from the aerofoil system. The aerofoils may be tilted with their tops towards the axis of symmetry of the system so as to lower the point of action of the resulting wind forces.

A practical embodiment of the invention is illustrated in the accompanying drawings in which Fig. 1 illustrates a construction particularly suitable for large vessels, Fig. 2 illustrates one of the submerged hulls, Fig. 3 is a plan view of the rudder of the submerged hull illustrated in Fig. 2 showing a portion of the mechanism for actuating the rudder tab, Fig. 4 is .a perspective view showing in detail the mechanism for reducing automatically the angle of the tab relatively to the rudder as the rudder swings, Fig. 5 is a semi-diagrammatical perspective view of the general control apparatus of the vessel. Figs. 6A, 6B and 6C are diagrammatical plan views of the vessel illustrated in Fig. 1 showing how the aerofoil system of the vessel is orientated when the vessel is sailing in different courses relatively to the Wind, Fig. 7 shows how the hydroplanes may be set to provide dynamic stability while the vessel is sailing.

Fig. 8 is a simplified diagrammatic perspective view of the parts of the vessel drawn in reduced scale to give a comprehensive representation of one practical embodiment of the invention.

In the drawings and referring first to Fig. 1, two aerofoils 1 tapering towards their tops are connected at the top by a horizontal spar 2 and are supported at their lower ends by a streamlined body 3 which latter is supported at its four corners by hulls 4 which, in normal operation, are submerged, the hulls 4 being connected to the body 3 by streamlined struts 5, the connection of the struts 5 to the body 3 being such that the hulls 4 can be rotated along with the struts 5 relatively to the body 3. The hulls 4 are fitted with water rudders 6 and hydroplanes 7. 8 denotes a wind vane supported by a boom 9 pivoted to the body 3 about a pivot 9A and projecting to the rear of the body 3. The rudder 6 carries a rudder tab 10 pivoted to the rudder 6 and connected by a rod 11 to one arm of a bell-crank lever 12 (Figs. 2 and 4), the bell-crank lever 12 being pivoted at 13 (Fig. 4) to a bracket 14 rotatably mounted on a screw-threaded sleeve 15 the purpose of which is explained later in the specification. The sleeve 15 is splined on a shaft 16 to which is attached a pinion 17 engaging the teeth of a sector 18 fastened to a fixed rudder post 19 supporting the rudder 6, the screw-threaded sleeve 15 being in engagement with a correspondingly screw-threaded hole in a cross member 20 in the rudder 6. The mechanism incorporating the parts represented by the reference numerals 14, 15, 16, 17, 18, 19, 20 is represented by a box numbered 21A in Fig. 8. The other arm of the bellcrank lever 12 is pivoted to one end of a rod 21 the other end of which is pivoted to one arm of a bell-crank lever 22 (Fig. 2) pivoted to a fixed pivot in the hull 4, the other arm of the bell-crank lever 22 being pivoted to one end of a rod 23 the other end of which is pivoted to one arm of a bell-crank lever 24 pivoted to a fixed support in the hull 4. The other arm of the bell-crank lever 24 presents a cam follower engaged with a cam groove 25 in a cylinder 26 fastened to a steering control shaft 27 passing down through the strut 5. The steering control shaft 27 carries a pulley 28 wrapped by the steering cables 29 and 30.

Referring to Fig. 5, 31 denotes a hollow shaft carrying a drum 32, the cables 29 and 30 (see Fig. 2) wrapping the drum 32 and being led around pulleys 33, 34, 35, and 36, 37, 38, respectively, the pulleys 35 and 38 of each cable 29 and 30 being mounted on. an associated frame 39A and movable in guideways by a tappet 39 coupled to a cam follower 40. The mechanism incorporating the parts represented by the reference numerals 39, 40 is represented by a box numbered 40A in Figs. 5 and 8. The cam follower is engageable with a groove 41 formed around the periphery of a swash plate 42 adapted to swing about pivots 43 mounted in the shaft 31, as a result of movement of the wind vane 8, or by direct control by a steersman in consequence of changes in the direction of the wind. The swash plate 42 is coupled by a link 44 and an arm 45 to a bar 46 slidable axially in the hollow shaft 31, said bar 46 being operatively coupled to one arm of a bell-crank lever 47 the other arm of which is coupled to a cross bar 48 pivoted at 49 at its centre. The ends of the cross bar 48 are connected individually to respective pedals Ed and 51. The cross bar 48 is also engageable with quadrants 52 and 53 fastened to a shaft 54 journalled in a bracket 55 pivoted to a fixed support 56 presenting two buffers 57 and 58 engageable with the quadrants 52 and 53 respectively. The quadrants, when swung to the positions against the buffers 57 and 5%, prevent the shaft 54 from swinging, and when swung to the positions indicated by dotted lines, cause swinging movement of the shaft 54 to be transmitted to the cross bar 43. This action provides accurate control of the Wind vane 3 in response to a predetermined movement of the pedals 5t}, 51. The shaft 54 carries, mounted freely therein and projecting from each end, stub shafts 59 and 60 connected to cables 61 and 62, respectively, coupled to the vane 8. The cables 61 and 62 from the vane S te the stub-shafts 59 and 60 are so' disposed that the boom 9 supporting the vane 8 may be swung without excessively altering the stressing of the cables 61 and 62. The shaft 54 also carries, fixed thereto, a lever 63 coupled by a link 64 to a lever 65 fixed to a shaft 66 carrying a crank 67 coupled by a rod 68 to a control lever 69 on a dash board 70. The mechanism incorporating the parts represented by'the reference numerals 47, 49, S2, 53, 55, 56, 57, 58, 5?, 6!), 63, 64, 65, 66, 67, 68, 69, is represented in Fig. 8 as a box numbered 54A. -The drum 32, which is wrapped by its steering cables 29, 36, carries one bevel gear element 71 meshing with a second bevel gear element 72 mountedon a shaft '7 3 carrying a course-setting wheel 74. This mechanical connection is shown for simplicity in Fig. 8 as a pulley and cable connection 74A.

There may be two or four cam followers 46 with their attendant mechanism for altering the effective lengths of the cables 29 and 36 arranged at a predetermined angle to one another around the periphery of the swash plate 42. Where two cam followers are provided one is operatively coupled to the tabs of the forward port hull and the after starboard hull, and the other is'operatively coupled to the tabs of the forward starboard hull and the after port hull. Where four cam followers are provided as shown in Fig. 8 each is coupled to the tabs of a respective hull.

Element 75 denotes a wheel operatively coupled to the pivot 9A of the boom 9 to set the angle of the boom 9 relatively to the aerofoil system 1, and 76 denotes a control lever adapted to lock the tabs 10 in their mid positions, e. g. by rotating and holding the hollow shaft 31 in the appropriate position.

Element 77 denotes a lever mounted in a ball socket '78 and carrying a sleeve 79 slidable on the lever 77. The sleeve 79 presents arms 80, each coupled to a cable 81 led around pulleys 82 and operatively coupled to an arm 81A projecting from a rod 81B adapted to slide axially in the respective shaft 27, the rod 81B being connected by a bell crank connection 81C to the respective tab 83 on the hydroplanes '7 carried by a respective hull 4 (see Figs. 1 and 2). The lever 77 carries an auxiliary lever 84 pivoted thereon and coupled by a rod 85 to the sleeve 79. 86 denotes a locking pin provided to hold the auxiliary lever 84 in its mid position in opposition to the spring 87.

The struts 5 (Fig. 2) each carry a toothed ring 88 meshing with a pinion 89 rotatable by a hand wheel 90 to align the hulls by hand when necessary.

Referring to Figs. 6A, 6B and 6C, Fig. 6A represents a vessel sailing close-hauled, 6B represents a vessel sailing on a reach, and 6C represents a vessel tacking to leeward. In all of these figures the arrows 91 represent the direction or" the true wind, the arrows 92 represent the course of the vessel and the arrows 93 represent the direction of the wind relatively to the vessel.

The boom 9 and the vane 8 are held in their mid positions when the vessel is at rest.

in practice, the vessel is operated in the following general manner. A detailed account of the operation of the mechanism in executing the following manoeuvres is given later in the specification.

Starting from rest at anchor or moored to a buy.- in the absence of a current in the water the vessel will ride head to wind at anchor or at the buoy with the boom 9 central, and the hulls 4 lying in the positions they occupied when the vessel was last in motion, or'at random. To prepare for starting, particularly if the space for manoeuvring is restricted, the hulls may be turned by hand to a direction some 120 or more from the wind. Exact alignment is not necessary. As the mooring line is released, the boom 9 is moved by the wheel 75 to a position about 12 off the centre-line. The action of the wind on the tail constituted by the vane 8 locked centrally on the boom 9 starts to rotate the vessel, the angle of incidence of the aerofoil system to the wind increasing, and the resultant force on the aerofoil system being almost along the direction in which the hulls are pointing. The lever 76 locking the rudder tabs 10 in their midpositions is actuated to release the tabs 10. The hulls 4 then assume the mean line determined by the Immediate setting of the course-setting control Wheel 74, and keel action by the hulls begins. The course-setting control wheel 74 is then altered to bring the vessel on to the desired true course. As the speed of the vessel increases, the direction of the wind appears to change, but through the consequent swinging action of the vane S the aerofoil system 1 is kept at a constant angle of incidence to the relative wind, i. e. the apparent direction of the wind, apart from a certain time-lag inthe operation of the mechanism, the particular angle of incidence being determined by the original manual setting of the boom 9 relatively to theaerofoils. The usual variations in wind strength with consequent acceleratio-ns and decelerations of the vessel will produce continuous variations of the relative wind direction, even if the true wind direction is steady, so that strictly to maintain a true course, the course line of the hulls 4 relatively to the fuselage 3 requires to be continually altered by angular movement of the wheel 74, this being the principal occupation of the helmsman. The most desirable setting of the boom '9 differs little between beating, reaching and running on either tack, and should generally be left untouched for considerable periods between changes of tack.

In conditions of equilibrium the relative wind will blow in a direction parallel to the boom 9 or at that small angle to the boom 9 which will deflect the vane 8 by whatever amount is necessary to alter the positions of the hulls 4 relatively to one another to provide the keel force necessary in the particular sailing conditions.

Except when it is desired to use the wind strength only in part, the angle of incidence of the wind on the aerofoils will always be within a few degrees of the stal ing angle, varying only slightly between sailing free and sailing close hauled on either tack.

Riding at anchor in a current.-In this case, While the aerofoil system 1 and the boom 9 are parallel to the direction of the wind, the hulls 4 lie heading into the current with enough steerage 'way to influence the tabs 10 immediately they are released by the lever 76. If the heading of the hulls 4 is too close to the wind to sail straight off the moorings merely by adjusting the boom 9 the momentum of the vessel relative to the current is enough to bring the hulls on to the proper course line, when the wheel 74 is set to the desired course, thereby actuating the tabs. In the case of a vessel lying to her own anchor, the act of hauling in the cable often sufiices' to give steerage way even in the absence of a current.

Normal tacking.-In tacking, four manoeuvres should be performed: (1') The course must be altered by about 116. (ii) The vessel must be rotated through some 86 (see explanation in IV below). (in) The boom 9 must be swung from 1ll3 to port to the same angle to starboard of the centre-line. (iv) The mean course line of the hulls relative to the fuselage must be changed from 15 to port to 15 to starboard of the centre-line, giving a change of hull direction 30 less than the change of course direction. In fact if the boom-setting control wheel 75 and the course-setting control wheel 74 are smoothly and simultaneously rotated from their settings for one tack to their settings for the other tack. the manoeuvres (i) and (ii) are performed automatically provided that the wind does not suddenly fall too light to provide differential steering by means of the vane 8; in such a case manual steering becomes necessary. Experience will show whether it is advantageous to move the two controls other than smoothly; it might, for example, be preferable to alter the course setting control wheel 74 sharply, and even to overshoot the final position to give the greatest curvature to the course; it will almost certainly be necessary to complete the change of boom position before the vessel has reached the new course, since the angular momentum acquired by the vessel in the manoeuvre would tend to lead to oscillation.

Tacking to leeward.Two possible conditions must be considered. (a) If the vessels speed remains in excess of the wind speed while tacking, the relative wind moves around in the same sense as the change of course. (b) If the initial speed is less than the wind speed, the relative Wind moves around in the opposite sense to the change of course. If, however, the ratio of the vessels speed to the wind speed falls from above to below unity in the course of the manoeuvre, the ensuing discontinuous change of wind direction takes the vessel aback, which is an inconvenience if not a danger. As the deceleration of the vessel at high speeds is considerable when the driving force is removed, it is unlikely that maneouvre (i) can ever be carried out safely. If necessary, then, the speed must first be reduced to below the wind speed, and manoeuvre (ii) performed. The vane steering will operate in the correct fashion to assist, but as the vessel must be rotated through nearly 180, and as the relative wind will be greatly diminished when the course is directly down wind, it will be advisable for the steersman to assist with the differential steering control by operation of the pedals 50 and 51. As an alternative, it is possible to wear ship, that is to bring her on to the wind, and bear away again.

Referring to Figs. 6A, 6B and 6C, which show a vessel sailing in several different courses, the aerofoil system is so orientated with respect to the relative wind indicated by the arrows 50 that a component of the aerodynamic force acting on the aerofoil system coincides with the course of the vessel. The hulls4, when directed one or two degrees to windward of the course, develop a force equal and opposite to the unwanted component of the aerodynamic force, that is, the component at right angles to the course.

During the performance of the previously described manoeuvres the mechanism operates as follows:

In the particular embodiment illustrated, the mean orientation of the hulls is determined by rotating the drum 32 by the course-setting wheel 74 acting through the shaft 73 and the bevel gear elements 72 and 71, or the cable and pulley connection 74A as illustrated in Fig. 8. The steering cables 29, 36 wrapping the several pulleys 28 are thereupon moved. Each pulley 28 consequently rotates, causing the associated shaft 27 and the cylinder 26 to rotate. The sinuous form of the groove 25 on the cylinder 26 causes the bell-crank lever 24 to swing, whereby to push or pull the rod 23, which, in turn, causes the bell-crank levers 22 and 12 to swing, the rod 11 connected to the rudder tab being thus pushed or pulled to move the tab it). When the tab 10 swings out of the plane of the rudder 6, a servo action takes place as follows. The slip stream flowing past the rudder 6 generates a force on the tab 10 which causes.

the rudder 6 to swing. When the rudder 6 swings, the sleeve 15, the splined shaft 16, and the pinion 17 to gether with the bell-crank lever 12 supported by the sleeve 15 swing bodily about the axis of the rudder post 19. The pinion l7 engaged with the teeth of the stationary sector 18 said pinion thus rotates and causes the sleeve 15 to rotate. Rotation of the sleeve 15 results in die sleeve 15 moving axially through the screwthreaded hole in the cross member 20, the axial movement causing the pivot 13 of the bell-crank lever 12 to be moved in a relatively vertical direction to the rudder 6 whereby to reduce the deflection of the tab 10 relatively to the rudder 6 as said rudder 6 swings in response to the steering wheel (see Fig. 4). If the vessel deviatesfrom its course the vane 8, which was formerly aligned with the direction of the relative wind 50, swings because of the apparent change of direction of the wind.

The swinging movement of the vane 8 pulls one of the cables 61 or 62 and causes the shaft 54 to swing. The quadrants 52 and 53 come against the bar 48 (the quadrants being in the positions for automatic operation of the mechanism shown by dotted lines in Fig. 5) and cause the bar 48 to swing, which swinging movement swings the bell-crank lever 47 and causes the bar 46 to slide axially through the shaft 31, the sliding action being communicated through the arm 45 and the link 44 whereby to cause the swash plate 42 to tilt about the pin 43. lies in a plane different from that it previously occupied. The movement of the swash plate 42 is communicated to the followers 49, each of-which is thereupon moved a distance the magnitude of which depends. on the instantaneous angular relationship of the follower on the periphery of the swash plate to the axis of the pin 43. As each follower 40 moves, the movement is communicated by the associated tappet 39 to the frame 39A and thus to the pulleys 35 and 38 whereby the effective lengths of the steering cables 29 and 30 are increased and decreased, relatively, or. decreased and increased respectively, the effect being to cause the corresponding pulley 28 to rotate whereby to cause the associated rudder tab 10 to swing and to communicate swinging movement to the associated rudder 6. When the vessel comes back on to its course, the vane 8 reverts to its original position, and the swash plate 42 also reverts to its original angle of tilt if any. The steering cables 29 and 30 thus revert to their original effective lengths so that the tabs 10 are returned to their original positions resulting in the rudders 6 also assuming their original positions. These normal conditions apply until the vessel deviates again from its course whereupon the same co.- recting movement is applied. If desired, steering can be performed manually by following the movement of a wind direction indicator, the swash plate 42 being thereupon tilted by operation of the pedals 59 or 51 instead of by movement of the vane 8. The pedals 50 or 51 can be operated to assist the vane 8.

From the foregoing it will be understood that there are two distinct operations involved in steering the vessel. A mean course for the four hulls is determined by the steering wheel 74-, and a differential steering efiect among the four hulls for the purpose of rotating the vessel or for producing a keel force to oppose the aerodynamic force is produced by the vane 8 or by the pedals 50 and 51.

When'the vessel is at anchor, the lever 76 is set to bring the tabs 10 and consequently the water rudders 6 to a central position and the boom 9 is swung by the wheel 75 to the position to maintain the aerofoil system at zero incidence to the actual wind. The vane 8 is locked in its mid position by manipulating the lever 69 to cause the shaft 54 to be rotated whereby to swing the quadrants 52 and 53 against the fixed buffers 57 and 58 as shown by the full lines in Fig. 5. The tabs 10; are locked in their mid position to provide the maximum degree of caster action of the hulls 4 to permit the vessel to respond to changes of wind direction and also to permit the hulls to swing to face into any current in the water.

The different angular displacements of the cam followers 40 around the swash plate 42 relatively to the axis of the pin 43 will result, when the swash plate 42 is tilted, in causing the several hulls 4 to assume positions at angles diverging by difiering slight amounts from the course of the vessel. This is necessary to maintain balance of the water forces acting on the hulls and to oppose the component of the aerodynamic force tending to cause drift, since the lateral thrusts from the hulls As the swash plate 42 tilts, the groove 41 now 7 are almost proportional to their angles of leeway, they will adjust themselves until the resultant keel force acts through the correct point on the fore and aft line.

When the vessel is tacking, all controls are more conveniently set for manual operation. The hulls 4 and the struts 5 may be so proportioned that the natural hydrostatic stability of the vessel is kept to a value not greatly in excess of that required for safety when the vessel is at rest. A low hydrostatic stability is desirable from the standpoint of sea kindliness. When sailing at all but the lowest speeds additional stability is provided by hydrodynamic couples generated by the hydroplanes 7. In Fig. 7 there is diagrammatically represented the forces acting when a vessel is sailing on the course illustrated in Fig. 6B. When on this course the tabs 83 of the hydroplanes 7 are so'defiected that the hydroplanes on the weather side of the vessel generate a negative lift tending to submerge the weather side of the vessel, and the hydroplanes on the lee side of the vessel are arranged to provide a positive lift tending to raise the lee side of the vessel out of the water. Compensation is thus made for the lateral thrust of the wind so that the vessel remains level or assumes only a small angle of heel. In certain conditions e. g., when crossing waves at high speed it may be found desirable so to arrange the hydroplanes 7 that all hydroplanes provide a degree of positive or negative lift to reduce or eliminate heaving of the vessel. In winds of a force greater than that which the vessel can usefully employ the angle of incidence of the aerofoil system 1 to the winds may be reduced. In this connection it may be remarked that rigid aerofoils possess the advantage of continuing to operate efficiently at low angles of incidence whereas soft sails begin to flap, and will tear if the flapping action is permitted to continue.

The hydroplanes are controlled by the lever 77. Move ment of the lever 77 in any direction is followed by the vessels tilting in the same direction if the water speed of the vessel is great enough. When the lever 77 is moved, the cables 81 are moved correspondingly to cause the rods 81B coupled thereto to slide through the shafts 27 and move the respective hydroplanes 7 up or down. When the auxiliary lever 84 is held in its mid position by the locking pin 86 there is no lift by the hydroplanes. When the locking pin 86 is withdrawn the auxiliary lever 84 may be moved to raise or lower the sleeve 79 on the lever 77 whereby the vessel may be caused to rise or fall bodily relatively to the water.

What is claimed is:

l. A sailing vessel, comprising a base member, a plurality of spaced interconnected submerged hulls attached to and supporting the base member, at least one aerofoil system incorporating at least one rigid aerofoil attached to and extending upwardly from the base member, substantially vertical struts respectively connecting said hulls to said base member, said hulls and said aerofoil system being relatively movable about vertical axes, a stationary rudder post fitted to each submerged hull, a water rudder pivoted to each rudder post, a toothed sector fastened to said rudder post, a pinion engaging the teeth of said sector, a splined shaft fixed to said pinion, an externally screw threaded sleeve slidable axially on said splined shaft, an element fixed to and movable with the rudder and having a screw thread engaging the screw thread on said sleeve, a bracket freely mounted for rotational movement on said sleeve but entrained to move axially with said sleeve, a bell crank lever having two arms pivoted to said bracket, a tab small in size relatively to the rudder and pivoted to the rudder adjacent to its free edge, a control rod connected at one end to one of the arms of the bell crank and connected at the other end to said tab, and steering means coupled to the other arm of the bell crank lever.

'2. A sailing vessel, comprising a base member, a plurality of spaced interconnected submerged hulls attached to and supporting the base member, at least one aerofoil system incorporating at least one rigid aerofoil attached to and extending upwardly from the base member, substantially vertical struts respectively connecting said hulls to said base member, said hulls and said aerofoil system being relatively movable about vertical axes, a water rudder pivoted to each hull, a tab pivoted to each rudder near the free edge thereof, means for swinging said rudders simultaneously and differentially through dilferent angles, said means including a swash plate, means for varying the angle of tilt of said swash plate, means for rotating said swash plate, followers engaging said swash plate, and means responsive to the movement of each follower when moved by the swash plate for influencing the setting of the tab pivoted to the associated rudder.

3. A sailing vessel as claimed in claim 2, including a movable wind vane, steering cables for each rudder tab, a steering drum connected to the swash plate and wrapped by the steering cables, a link connected to the swash plate near its periphery, a bar slidable axially of said drum and connected to said link, a cross bar pivoted at its center and operatively connected to said first-mentioned bar, control pedals coupled to said first-mentioned bar, and means for operatively connecting said cross bar to the wind vane.

4. A sailing vessel as claimed in claim 3, including a shaft pivoted at its center and rotatable about its pivot axis, means coupling the ends of the shaft to the wind vane, spaced quadrants fastened to the shaft, spaced fixed buffers, said quadrants being engageable at one rotational position of said shaft respectively with said fixed buffers and at another rotational position with the cross bar, and control means for rotating said Shaft.

5. A sailing vessel as claimed in claim 2, including a boom, a movable wind vane carried by said boom, and means for operatively coupling said wind vane to the swash plate to tilt said swash plate through an angle proportionate to the magnitude of each movement of said wind vane relatively to said boom.

6. A sailing vessel as claimed in claim 2, including steering means consisting of steering cables for each rudder tab including pulleys around which each steering cable is led, and a steering drum wrapped by the steering cables, said pulleys being positioned to provide at least one loop in each cable, one of said pulleys being at the bend of each loop of the cable, said pulley at the bend of said loop being connected to a respective follower and being movable transversely of said cable to alter the length of the loop on movement of said follower.

7. A sailing vessel as claimed in claim 2, including steering mechanism comprising a steering cable for each rudder tab, a steering drum wrapped by the steering cables, a shaft carrying the drum, and a transverse pin carried by the shaft and located diametrically of the drum, the swash plate being mounted on the pin, the several parts of the mechanism being so located relatively to one another that when the steering drum is rotated during the steering of the vessel the axis of said pin is always at right angles to the desired course of the vessel.

8. A sailing vessel, comprising a base member, a plurality of spaced interconnected submerged hulls attached to and supporting the base member, at least one aerofoil system incorporating at least one rigid aerofoil attached to and extending upwardly from the base member, substantially vertical struts respectively connecting said hulls to said base member, said hulls and said aerofoil system being relatively movable about vertical axes, a water rudder fitted to each hull, a servo-system for operating each water rudder, said servo-system including a tab small in size relatively to the rudder pivoted to the rudder adjacent to its free edge, steering cables coupled to each tab, a rotatable drum wrapped by said steering cables, a shaft extending vertically down through aaoaoss fig Try each strut into the respective hull, the steering cables for said hull being operatively coupled to said shaft, a cylinder having a peripheral sinuous groove fastened to the lower end of said vertical shaft, and a follower engaging said groove, said follower being operatively coupled to the tab of the rudder carried by the respective hull.

9. A sailing vessel, comprising a base member, a plurality of spaced submerged hulls attached to and supporting the base member, at least one aerofoil system incorporating two rigid spaced aerofoils attached to and extending upwardly from the base member, said aerofoils tapering and converging toward their tops, a horizontal spar connecting and linking the tops of said aerofoils, and substantially vertical struts respectively connecting said hulls to said base member, said hulls and said aerofoil system being relatively movable about vertical axes,

10. A sailing vessel as claimed in claim 9, in which the base member is connected between the two aerofoils near the lower extremities thereof.

11. A sailing vessel comprising a base member, a plurality of spaced submerged hulls attached to and supporting the base member, rudders pivoted to said hulls, at least one aerofoil system incorporating at least one rigid aerofoil attached to and extending upwardly from the base member, substantially vertical struts respectively connecting said hulls to said base member, said hulls being normally freely rotatable relatively to said aerofoil system under the influence of said rudders, manual steering means adapted to provide a setting of said rudders according to the desired course of the vessel, and a wind vane connectible to said rudders to provide control of said rudders additional to the control provided by said manual steering means.

12. A sailing vessel as claimed in claim 11, including a boom, said Wind vane carried by said boom, and a variable coupling means between said wind vane and said rudders for setting said boom at a predetermined angle to the aerofoil system without disturbing the rudder settin-gs for a particular course, said coupling means being iii adapted to cause subsequent movement of said Wind vane out of line with the boom to produce deflection of said water rudders.

13. A sailing vessel as claimed in claim 11, including a servo-system operatively associated with each rudder for effecting its operation.

14. A sailing vessel as claimed in claim 11, including a servo-system for operating each rudder, said servo-system including a tab small in size relatively to the rudder and pivoted thereto adjacent to its free edge, steering cables coupled to each tab, and a rotatable drum wrapped by said steering cables.

15. A sailing vessel as claimed in claim 11, including hydroplanes carried by each hull, a tab pivoted to each hydro-plane near its free edge, and servo-means for operating each tab.

16. A sailing vessel as claimed in claim 11, including hydroplanes carried by each hull, a ball mounting, a lever rockably mounted on said ball mounting, a sleeve slidable on said lever, arms projecting from said sleeve, each arm being connected to the hydroplanes of said hull, and an auxiliary lever mounted on said first-mentioned lever and operatively coupled to said sleeve to locate said sleeve in a predetermined axial position on said first-mentioned lever.

References Cited in the file of this patent UNITED STATES PATENTS 1,303,839 Henderson May 13, 1919 1,422,542 Creed .1 July 11, 1922 1,753,399 Blair Apr. 8, 1930 2,484,687 Carl Oct. 11, 1949 2,491,541 WoOdin Dec. 20, 1949 FOREIGN PATENTS 198,649 Great Britain May 1, 1924 403,416 Germany Sept. 29, 1924 559,619 Great Britain 1. Feb. 28, 1944 568,209 Great Britain Mar. 23, 1945 861,518 Germany Jan. 5, 1953 

